Filamentary yarn lubricating apparatus



1967 o. A. HlTT FILAMENTARY YARN LUBRICATING APPARATUS Filed April 6, 1966 United States Patent 3,336,900 FILAMENTARY YARN LUBRICATING APPARATUS Otha Allen Hitt, Richmond, Va., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Apr. 6, 1966, Ser. No. 540,555 3 Claims. (Cl. 118-248) This invention relates generally to the manufacture of filaments, yarns, threads and the like and, more particularly, to an apparatus for applying finish to a moving threadline.

In the manufacture of filamentary yarn from synthetic polymers such as nylon, it is the practice to apply a liquid finishing composition to the yarn prior to packaging. The finish functions principally to lubricate and protect the filaments from rubbing and abrasive action on guide surfaces and to hold together the substantially parallel filaments which form an untwisted yarn so that it may be wound into a satisfactory package.

Normally, finish is applied by advancing yarn in contact with the exposed surface of a roll which dips into a finish pool. The roll may be covered at the point of contact with a stationary layer of gauze. Finish applied in this manner migrates within the filament bundle at a uniform level. However, in a high speed spin-draw process, particularly at low levels of finish-on-yarn, the brief interval between application of finish and drawing of the yarn precludes finish-leveling by migration and leads to a deterioration in yarn quality as evidenced by a sharp increase in the frequency of broken filaments.

It is the object of this invention to provide an improved apparatus for applying finish to filamentary yarns, threads and the like. A more specific objective is to provide for uniform finish application, at low levels of finishon-yarn and without adverse effect on yarn quality or package formation.

The above and other objects have been accomplishedin a yarn-handling installation which includes a finish roll engaged by a gauze skirt at the point of contact with a continuously advancing filamentary yarn and also by the spreader of the present invention. The latter is comprised of a support, an arm swingably mounted on the support, spring means biasing the arm toward the finish roll and an elongated arcuate shoe mounted on the arm for pivotal movement into alignment with the roll. The shoe carries another gauze skirt also positioned at the point of contact. Thus, yarn is pressed and spread by a spring action in its advance between two gauze skirts, one of which receives finish from the roll.

In the accompanying drawing, FIGURE 1 is a schematic illustration of a process installation into which the finish applicator of the present invention has been incorporated. FIGS. 2 and 3 are end and top views of the finish applicator. FIG. 4 is a fragmentary front view of the spreader shown in FIGS. 2 and 3.

The process installation chosen for purposes of illustration in FIG. 1 includes a quenching chimney to and through which filamentary yarn 12 is spun from a spinneret. From chimney 10, yarn 12 advances as two converging bundles through a finish applicator. The split yarn is combined on a feed roll 20, advanced in several wraps over a snubbing device 22 by draw roll 24 and traversed onto a package 26. The finish applicator includes support structure 28, a relatively long guide bar 30, a grooved convergence guide 32 and the intermediate apparatus which has been detailed in FIGS. 2-4.

With reference to FIGS. 2 and 3, the intermediate apparatus 15 has a rotatably driven finish roll 34 which dips into liquid finish contained in a pan 36. Support structure 28 includes a rod 38 from which a first gauze skirt 40 3,336,900 Patented Aug. 22, 1967 is suspended. As illustrated, skirt 40 engages roll 34 at the point of contact with the split bundles 12' (FIG. 3). Adjacent roll 34, there is an elongated, arcuate shoe 42 to which one end of a rod 44 is afiixed. Rod 44 carries a second gauze skirt 46 which is thereby positioned opposite skirt 40 and also contacts converging bundles 12' in their advance between guides 30, 32. The contact surface of shoe 42 departs arcuately from roll 34 above the point of contact and terminates just below that point.

As best shown in FIGS. 2 and 4, shoe 42 is affixed to a bearing sleeve 48 which is rotatable on the upturned end of a swing arm 50. At its upper terminus, arm 50 has a threaded socket for a retaining bolt 52. This pivotal mounting facilitates alignment of shoe 42 with roll 34. Arm 50 has a downwardly turned, threaded length at its other end which is rotatable in a bearing sleeve 54 fixedly attached to support structure 28. Between the bottom of sleeve 54 and a nut 56, there is a spring 58 which tends to pull arm 50 downwardly in sleeve 54. The upper, angularly disposed end of sleeve 54 serves as a cannning surface for a follower 60 on arm 50. When placed in compression by adjustment of nut 56, spring 58 urges follower 60 downwardly on the camming surface and thereby serves as the means for biasing swing arm 50 toward roll 34 and maintaining a slight positive pressure on yarn advancing between gauze skirts 40, 46.

In operation, the action of spring 58 on follower 60 urges shoe 42 against roll 34 and the pivotal mounting of sleeve 48 maintains alignment between shoe 42 and roll 34 to insure that equal pressure is applied throughout the Width of both filament bundles.

In practice, it has been found that use of an arcuate shoe carrying a gauze skirt pressing lightly over the filament bundles at the points of contact on the finish roll skirt results in a more uniform finish application to all filaments. Consequently, a yarn structure is produced which gives much improved performance in the drawing operation. Quality of the drawn product is also improved. Another important advantage of this invention is that higher spinning speeds can be employed to give greater productivity whilestill maintaining uniform finish application at relatively low levels of finish-on-yarn. Accordingly, the applicator disclosed herein is particularly advantageous in a coupled spin-draw process where a necessary characteristic of the finish may be undesirable in the end product. With an effective application of the processing finish, at high speeds and at low levels of finish-on-ya-rn, a post-application of product finish is facilitated.

Generally, the pressure exerted by the shoe should be sutficient to maintain positive contact with the finish roll skirt but should not be enough to cause excessive drag on the yarn. The optimum pressure would be expected to vary depending on yarn denier and the number of filaments. A range of from 20 to grams would appear satisfactory to cover most applications.

Variations and modifications of the illustrated finish applicator will occur to those skilled in the art without departing from the spirit of my invention which accordingly is intended to be limited only by the scope of the appended claims.

Having thus described the invention, what is claimed as new and desired -to be secured by Letters Patent is:

1. In a yarn-handling installation including a finish roll engaged by a gauze skirt at the point of contact with an advancing filamentary yarn, a spreader comprising: a support; a swing arm on the support; spring means biasing the arm toward the roll; and an elongated shoe mounted on the arm for pivotal movement relative thereto into alignment with the roll, said shoe carrying a sec ond gauze skirt also positioned at said point of contact.

2. The yarn-handling installation of claim 1 wherein said shoe has an arcuate contact surface which terminates just beyond said point of contact in the direction of yarn References Cited UNITED STATES PATENTS 7/1891 Johnson 118226 7/1911 Wheeler 118248 4 Harris 113-226 X Mayer 118226 Carlson 118226 X Finzel 264-290 Galatioto 118226 X Matter 118248 X Knopp 264-29O X Sharp 264130 CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Assistant Examiner. 

1. IN A YARN-HANDLING INSSTALLATION INCLUDING A FINISH ROLL ENGAGED BY A GAUZE SKIRT AT THE POINT OF CONTACT WITH AN ADVANCING FILAMENTARY YARN, A SPREADER COMPRISING: A SUPPORT; A SWING ARM ON THE SUPPORT; SPRING MEANS BIASING THE ARM TOWARD THE ROLL; AND AN ELONGATED SHOE MOUNTED ON THE ARM FOR PIVOTAL MOVEMENT R ELATIVE THERETO INTO ALIGNMENT WITH THE ROLL, SAID SHOE CARRYING A SECOND GAUZE SKIRT ALSO POSITIONED AT SAID POINT OF CONTACT. 